#include <string.h>

#include "fsctl/fugue.h"
#include "fsctl/fugue/sector.h"
#include "fsctl/fugue/utils.h"
#include "fsctl/fugue/fat.h"

//---
// Public
//---

/* fugue_fs_mount() : try to initialize the FS */
int fugue_fs_mount(fugue_fs_t *fsinfo, void *addr)
{
    fugue_fs_t fs;
    struct fugue_fat_vbr *vbr;
    uintptr_t FAT0_addr;
    uintptr_t FAT1_addr;
    int CountofClusters;
    int RootDirSectors;
    int TotCapacity;
    int DataSec;
    void *type;
    int FATz;

    if (fugue_sector_is_vbr(addr) != 0)
        return -1;
    vbr = addr;

    //---
    // determine the number of cluster
    // @note
    // - hardcoded for FAT12 and FAT16
    //---

    RootDirSectors  = FAT_WORD(vbr->BPB_RootEntCnt) * 32;
    RootDirSectors += FAT_WORD(vbr->BPB_BytsPerSec) - 1;
    RootDirSectors /= FAT_WORD(vbr->BPB_BytsPerSec);

    DataSec  = FAT_WORD(vbr->BPB_RsvdSecCnt);
    DataSec += FAT_WORD(vbr->BPB_FATSz16) * vbr->BPB_NumFATs;
    DataSec += RootDirSectors;
    DataSec  = FAT_WORD(vbr->BPB_TotSec16) - DataSec;

    CountofClusters  = DataSec;
    CountofClusters /= vbr->BPB_SecPerClus;

    TotCapacity  = DataSec;
    TotCapacity *= FAT_WORD(vbr->BPB_BytsPerSec);

    if (CountofClusters < 4085) {
        type = "FAT12";
    } else if (CountofClusters < 65525) {
        type = "FAT16";
    } else {
        type = "FAT32";
    }

    //---
    // Analysing FAT intergrity
    // @note
    // - hardcoded for two Fugue
    // - Fugue seems use a static offset of its FAT : 5120 (10 sectors)
    // - Fugue doesn't have same sized FAT (FAT0=4608 && FAT1=512)
    //---

    //FATz  = FAT_WORD(vbr->BPB_FATSz16);
    //FATz *= FAT_WORD(vbr->BPB_BytsPerSec);
    //FATz *= vbr->BPB_NumFATs;
    FATz = 5120;

    FAT0_addr  = FAT_WORD(vbr->BPB_RsvdSecCnt);
    FAT0_addr *= FAT_WORD(vbr->BPB_BytsPerSec);
    FAT0_addr += (uintptr_t)vbr;

    FAT1_addr  = 4608;
    FAT1_addr += FAT0_addr;

    //---
    // Save calculated information
    //---

    memset(&fs, 0x00, sizeof(fugue_fs_t));
    fs._private.vbr = addr;
    fs.props.type = type;
    fs.props.sector_data_nb = DataSec;
    fs.props.sector_root_nb = RootDirSectors;
    fs.props.cluster_nb = CountofClusters;
    fs.props.cluster_size = vbr->BPB_SecPerClus * 512;
    fs.props.cluster_nb_sector = vbr->BPB_SecPerClus;
    fs.props.capacity  = TotCapacity;
    fs.props.fats_size = FATz;
    fs.props.fat0_size = 4608;
    fs.props.fat1_size = 512;
    fs._private.fat0 = (void*)FAT0_addr;
    fs._private.fat1 = (void*)FAT1_addr;
    fs._private.root = (void*)(FAT0_addr + FATz);

    if (fugue_fat_is_vaild(&fs) != 0)
        return -1;
    memcpy(fsinfo, &fs, sizeof(fugue_fs_t));
    return 0;
}